[Evaluation of a spectrophotometric technique for plasmatic haemoglobin determination on Konelab 30]. / Evaluation d'une technique spectrophotométrique pour le dosage de l'hémoglobine plasmatique sur Konelab 30(TM).

INTRODUCTION: the measurement of plasma haemoglobin is utilized in the evaluation of various haemolytic phenomenons, especially at the time of sampling. Besides, the methods used to titrate plasmatic haemoglobin, an analysis which is of great interest to cardiac surgery, must be very accurate, because plasmatic levels are much lower than those found in whole blood. BACKGROUND: the purpose of this work is to present a new technique for direct determination of plasmatic haemoglobin. MATERIAL AND METHODS: this method was studied and adapted on a multiparametric analyzer Konelab 30 (Thermo Electron Corporation). The correlation was assessed with a Sigma Diagnostics spectrophotometric method, using the 3,3',5,5'-tetramethylbenzidine (TMB), a non carcinogenic reagent. The reaction of haemoglobin with TMB was studied with a SECOMAM S500P UV-Visible spectrometer. RESULTS AND DISCUSSION: the method demonstrates linearity, precision, and sensitivity suitable for clinical use and not affected by the presence of bilirubin, nor triglycerides. The method was precise (CV < 1,00%), accurate (CE < 5,00%) and showed excellent recovery of haemolysis (R > 0,95). The CV for the automated assay was less than 1%. Reference ranges were studied and lithium heparinate seems to be the best anticoagulant to use so as to minimize haemolysis. CONCLUSION: the studied technique is practical, specific, accurate, fast, reliable and inexpensive, and was adopted in emergency as in daily routine in our laboratory for plasmatic haemoglobin determination in various situations.

[Adaptation of Biomerieux enzymatic UV ammonia on Konelab analysers]. / Adaptation de l'ammonium enzymatique UV de BioMérieux sur automates Konelab.

INTRODUCTION: Circulating ammonia in normal patients is relatively low, despite the fact that ammonia is continually produced from endogenous amino acid metabolism. The physiopathological interest of plasmatic ammonia determination lies primarily in its relationships to hepatic insufficiency (cirrhotic or neoplasic), or the diagnosis and the forecast of the Reye's syndrome. OBJECTS: This study describes an evaluation of plasmatic ammonia determination by the UV end point enzymatic method using GLDH on KONELAB(TM) analyzers. METHODS: The glutamate dehydrogenase (GLDH : EC.1.4.1.3) catalyses the reducing amination of alpha-cetoglutarate in the presence of NH(4)(+) and of NADPH, H(+) to form glutamate and NADP(+). The reduction of NADPH,H(+)'s concentration, directly proportional to ammonia rates, is evaluated at 340 nm. All the conditions were met to optimize the method, while covering a satisfying field of measurement. RESULTS AND COMMENTS: The evaluation of the modified method showed a good precision (repeatability: CV < 4 %; interserial reproducibility: CV from 2.01 to 2.93 %; Intraserial reproducibility: CV equal to 0.67%) and a very good accuracy. The field of measurement extends from 27 to 250 micromol/L, with a limit of detection (L(D)) lowered to 0.325 micromol/L. CONCLUSION: The adapted technique is simple, fast, inexpensive and especially automatizable. It is in addition reliable and chiefly more sensitive, adapting particularly to the determination of plasmatic ammonia in urgency as in routine within our laboratory.

[Determination of urinary citrates by an alternative of Millan's method]. / Détermination des citrates urinaires par une variante de la méthode de Millan.

INTRODUCTION: the physiopathological interest of the determination of urinary citrate lies primarily in its relationships to the lithiasic processes. Indeed, the citrate is a powerful complexing agent of calcium able to lower urinary supersaturation of oxalate and phosphate of calcium. OBJECTS: this study describes a revaluation of the determination of urinary citrates by the colorimetric method of Millan. METHODS: the principle of the method rests on the quantification of the yellow complex formed with iron chloride III and the urinary citric acid, measurable at 390 nm in acidic medium. All the conditions were combined to optimize it, while covering a satisfying field of measurement. RESULTS AND COMMENTS: the evaluation of the modified method showed a good precision (repeatability: CV from 0,18 to 3,42%; intraserial reproducibility: CV from 1,87 to 3,44 %; interserial reproducibility: CV from 2,15 to 5,52%) and a very good accuracy. The field of measurement extends up to 17,0 mmol/L, with a limit of detection (L(D)) lowered to 0,2 mmol/L (Vs 1,48 mol/L for the original method). All analytical performances are improved by automation with a L(D) = 0,09 mmol/L and a limit of linearity extended to 18 mmol/L. CONCLUSION: this modified, simple, fast, inexpensive and easily automatizable technique, seems to be reliable and especially more sensitive, adapting particularly to the detection of subjects suffering a deficit of citrate secretion, one of most significant inhibiting agent of lithiasis kidney formation.

[Emphysematous pyelonephritis: a case report]. / La pyélonéphrite emphysémateuse: à propos d'un cas guéri.

Diabetic patients with urinary tract infections had a certain risk of developping emphysematous pyelonephritis with gas producting bacteria. This disease was accompagned with high mortalité. We will report one case who was treated successfully by high dose antibiotic regim and emergency nephrectomy.